<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <button onclick="send()">发送</button>
  <script>

    const ws = new WebSocket('ws://localhost:9999/test-ws')

    ws.onopen = function(mevt) {
      console.log('客户端已连接')
    }
    ws.onmessage = function(mevt) {
      console.log('客户端收到消息: ' + mevt.data)
    }
    ws.onclose = function(mevt) {
      console.log('连接关闭')
    }

    function send () {
      ws.send('hi');
    }

  </script>
</body>
</html>